Answer: (A) Inside of single quotes
Step-by-step explanation:
The variable substitution or we can say that expansion occur inside the single quotes because the generation of the file name typically happened inside the single quotes only.
When we enclosing the character and different types of variable with the single quotes ( ' ) then, it basically represent the actual value of the characters. In this way, the estimation of any factor can't be perused by single statement and a solitary statement can't be utilized inside another single quote statements.